Study objective: To evaluate the relationship between
the adequacy of antimicrobial treatment for bloodstream infections and
clinical outcomes among patients requiring ICU admission.
Design: Prospective cohort study.
A medical ICU (19 beds) and a surgical ICU (18 beds) from a
university-affiliated urban teaching hospital.
Patients: Between July 1997 and July 1999, 492 patients
were prospectively evaluated.
Prospective patient surveillance and data collection.
Results: One hundred forty-seven patients (29.9%) received
inadequate antimicrobial treatment for their bloodstream infections.
The hospital mortality rate of patients with a bloodstream infection
receiving inadequate antimicrobial treatment (61.9%) was statistically
greater than the hospital mortality rate of patients with a bloodstream
infection who received adequate antimicrobial treatment (28.4%;
relative risk, 2.18; 95% confidence interval [CI], 1.77 to 2.69;
p < 0.001). Multiple logistic regression analysis identified the
administration of inadequate antimicrobial treatment as an independent
determinant of hospital mortality (adjusted odds ratio [AOR], 6.86;
95% CI, 5.09 to 9.24; p < 0.001). The most commonly identified
bloodstream pathogens and their associated rates of inadequate
antimicrobial treatment included vancomycin-resistant enterococci
(n = 17; 100%), Candida species (n = 41; 95.1%),
oxacillin-resistant Staphylococcus aureus (n = 46;
32.6%), coagulase-negative staphylococci (n = 96; 21.9%), and
Pseudomonas aeruginosa (n = 22; 10.0%). A
statistically significant relationship was found between the rates of
inadequate antimicrobial treatment for individual microorganisms and
their associated rates of hospital mortality (Spearman correlation
coefficient = 0.8287; p = 0.006). Multiple logistic regression
analysis also demonstrated that a bloodstream infection attributed to
Candida species (AOR, 51.86; 95% CI, 24.57 to 109.49; p < 0.001),
prior administration of antibiotics during the same hospitalization
(AOR, 2.08; 95% CI, 1.58 to 2.74; p = 0.008), decreasing serum
albumin concentrations (1-g/dL decrements) (AOR, 1.37; 95% CI, 1.21 to
1.56; p = 0.014), and increasing central catheter duration (1-day
increments) (AOR, 1.03; 95% CI, 1.02 to 1.04; p = 0.008) were
independently associated with the administration of inadequate
administration of inadequate antimicrobial treatment to critically ill
patients with bloodstream infections is associated with a greater
hospital mortality compared with adequate antimicrobial treatment of
bloodstream infections. These data suggest that clinical efforts should
be aimed at reducing the administration of inadequate antimicrobial
treatment to hospitalized patients with bloodstream infections,
especially individuals infected with antibiotic-resistant bacteria and